1. Field of the Invention
The present invention relates to a linear compressor, and more particularly to a linear compressor capable of minimizing gas suction loss of the compressor and reduce manufacturing costs by adopting a direct gas suction system in which a gas suction pipe is extendedly provided to an inner side of a piston of a compressor unit.
2. Description of the Conventional Art
FIG. 1 is a cross-sectional diagram illustrating an example of a conventional compressor. As shown therein, the compressor is mainly provided with a predetermined-shaped hermetic vessel 1 in which a gas suction pipe 2 is provided at one side thereof, a compressor unit 10 disposed in the hermetic vessel 1 in a horizontal direction, an oil supply means 3 disposed out of the compressor unit 10 at a bottom part of the hermetic vessel 1 and a plurality of springs 4 provided between a lower part of the unit 10 and the hermetic vessel 1 for elastically supporting the the compressor unit 10.
More specifically, the compressor unit 10 includes a cylinder 11 in which an oil path 11a is provided, a cover 12 coupled with an end side of the cylinder 11 and having a through hole 12a formed in a center portion thereof, first and second lamination 13, 14 disposed at an outer surface of the cylinder 11 having a predetermined distance to each other, a valve assembly 15 coupled with the other end side of the cylinder 11 by covering a hole thereof, a movable unit 16, to which a magnet 19 is attached, disposed between the first and second lamination 13, 14 for linearly reciprocating and having an opening 16a in a center portion thereof, a piston 17 formed with the movable unit 16 as a single unit and reciprocating in the cylinder 11, first and second springs 20, 21 elastically supporting the reciprocation of the piston 17, a cylindrical first muffler 22 of which an end portion is fixedly attached to the through hole 12a of the cover 12 and a second muffler 23 of which an end portion is fixedly attached to the opening 16a of the movable unit 16 and the other end portion is formed by being extended into the piston 17 for a predetermined length.
Here, numerals 24 and 25 are an oil supply pipe and an oil discharge pipe, respectively.
In such linear compressor, when a power is applied to the compressor unit 10, the movable unit 16 linearly reciprocates between the first lamination 13 and the second lamination 14 and also the piston 17 linearly reciprocates in the cylinder 11 by virtue of the reciprocation of the movable unit 16. Then, in accordance with the reciprocation of the piston 17 in the cylinder 11, a refrigerant gas flowed into the hermetic vessel 1 is sucked into a compression chamber of the cylinder 11 through a refrigerant flow channel 17a provided in the piston 17 and compressed therein, and the compressed refrigerant gas is exhausted through the valve assembly 15, the above process being repeatedly performed.
Here, a general refrigerating cycle unit of the linear compressor is provided such that a gas supplied from an evaporator is flowed into the hermetic vessel 1 through the gas suction pipe 2 communicated with the one end side of the vessel 1 and a part of the gas is directly flowed via the first and second mufflers 22, 23 and a remainder first fills the hermetic vessel 1, then is sucked into the compression chamber of the cylinder 11 through the first and second mufflers 22, 23 by pressure difference during the reciprocation of the piston 17 and compressed and exhausted by the compressive reciprocation of the piston 17.
Further, in the reciprocation of the piston 17, oil O filled in the bottom part of the hermetic vessel 1 passes through the oil supply means 3 and then oil supply pipe 24, and is discharged through the oil discharge pipe 25 after lubricating a portion between the piston 17 and the cylinder 11. In the conventional linear compressor, the gas is partly sucked into the compression chamber of the cylinder 11 through the first and second mufflers 22, 23 after filling the hermetic vessel 1.
However, since the one end portion of the gas suction pipe 2 is located between the hermetic vessel 1 and the compressor unit 10 and thus an atmosphere in the hermetic vessel 1 is heated by, for example, a motor, the gas flowed into the gas suction pipe 2 is also heated in certain degree. Therefore, the gas sucked into the compression chamber of the cylinder 11 through the first and second mufflers 22, 23 has been already preheated and thereby gas suction loss is incurred in accordance with of the gas volume ratio, which results in deterioration of the suction efficiency of the compressor.